DESCRIPTION (Adapted from applicant's description): This proposal will evaluate the effectiveness of a new drug combination for the induction of ovulation in anovulatory women with polycystic ovary syndrome (PCOS), a disorder affecting about 5% of women of reproductive age, characterized by anovulation with loss of menstrual cyclicity and hyperandrogenism, often resulting in hirsutism or acne. Induction of ovulation is necessary to restore fertility to women with PCOS and anovulation. The standard first-line treatment is with oral clomiphene citrate, an anti-estrogenic agent which increases endogenous FSH secretion. This study will examine whether clomiphene can be more effective in inducing ovulation if given concomitantly with troglitazone, an insulin sensitizer which lowers circulating insulin levels. Women with PCOS selected for previous resistance to clomiphene ovulation induction will be randomized to receive either troglitazone or placebo for a 2-month accommodation period and then will undergo attempted ovulation induction with clomiphene using standard regimens. If unsuccessful, the clomiphene dose will be increased in subsequent cycles according to standard practice in an effort to achieve ovulation. Ovulatory outcome, assessed by serum progesterone levels, will be compared between troglitazone and placebo groups and correlated with correction of hyperinsulinemia and with changes in baseline gonadotrophin, sex steroid and binding globulin (SHBG) levels.